I always think if Pakistan plays against India regularly (in bilaterals), it somehow brings the best out of them and they become a competitive side. It was a case even in late 90s, when India started to become better side with players like Dravid, Ganguly, Sehwag and then through 2000s - Yuvaraj, Dhoni... still Pakistan was competitive somehow. But they somehow falter in World Cups, even when they had strong teams in past. So Pakistan doing badly now against India (they play only in ICC tournaments & Asia Cups) doesn't imply that they will do badly in bilaterals.
Pakistan's cricket genes is such that they are keen to play against India. And that will bring the best out of them (players like Shoaib Akther emerged solely with the same intensity and passion!) So don't be surprised if Pakistan become a stronger team when they start playing against India regularly again... You will see a lot of quality players start emerging...
India on the other hand has developed into a professional team, and whether they play against Pakistan or not doesn't matter to them. (But its true that India wish to play against Pakistan for financial reasons - to make more money! That's why there are ICC Matches & both teams pooled in same group! But Pakistan want to play against India more for passion)
In the past India lacked professionalism and that's the reason why they used to lose badly against Pakistan in bilaterals but won against them in world cups because Pakistan's team tend to become nervous/over-excited when they play against India and it can create issues in bigger games! But Pakistan's intensity used to help them dominate India in normal matches.
Hence if Pakistan plays India regularly, I am sure they are going to be as competitive as SENA teams against India. To think that they will reach the level of West Indies is stupidity! Except ICC Matches, I think Pakistan can give tough time to India in bilaterals. Don't be surprised if they do something similar to what NZ did to India in home tests especially whenever India slip in professionalism (like how they played worn out cricketers against NZ and paid for it)